1. Field of the Invention
The subject invention relates to a vehicle hubcap, and more particularly, to a vented plug for use with a hubcap assembly installed on the wheel end of a heavy duty trailer or truck.
2. Background of the Related Art
In tractor and trailer wheel end axle assemblies, particularly those employed on large trailers and semi-trailers and tractors, the wheel is mounted on a fixed axle or spindle for rotation thereabout. The hub of the wheel defines a lubricant chamber about the end of the spindle in association with the wheel bearings. A quantity of lubricant is maintained in the lubricant chamber or wheel housing to continuously bath the bearings. A hubcap is used to enclose the lubricant chamber and, for maintenance purposes, the hubcap is oftentimes provided with a transparent end wall to readily observe the lubricant chamber.
Since the operation of a truck or trailer results in the heating of the fluid lubricant with the wheel housing, it has been found desirable to ventilate the wheel housing and provide for pressure equalization between the lubricant chamber and the surrounding atmosphere. It has also been found that water and foreign matter may be injurious to the wheel bearings. Therefore, provisions must be made to prevent such contaminates from entering the lubricant chamber by way of the ventilating features.
The subject invention provides a novel plug dimensioned and configured for reception in the end wall of a hubcap which includes features for ventilating the wheel housing while preventing the egress of fluid lubricants from the lubricant chamber and the ingress of water and foreign matter into the lubricant chamber.